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authorHarshit Mogalapalli <harshit.m.mogalapalli@oracle.com>2022-04-13 04:42:51 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-20 09:08:31 +0200
commit1316c28569a80ab3596eeab05bf5e01991e7e739 (patch)
tree8a3425a702ccb0a8a0ac7586c2f57a5336b8b8ef
parent9d243aff5f7e6b04e907c617426bbdf26e996ac8 (diff)
cifs: potential buffer overflow in handling symlinks
[ Upstream commit 64c4a37ac04eeb43c42d272f6e6c8c12bfcf4304 ] Smatch printed a warning: arch/x86/crypto/poly1305_glue.c:198 poly1305_update_arch() error: __memcpy() 'dctx->buf' too small (16 vs u32max) It's caused because Smatch marks 'link_len' as untrusted since it comes from sscanf(). Add a check to ensure that 'link_len' is not larger than the size of the 'link_str' buffer. Fixes: c69c1b6eaea1 ("cifs: implement CIFSParseMFSymlink()") Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--fs/cifs/link.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/cifs/link.c b/fs/cifs/link.c
index 9451a7f6893d..a89b8ff82040 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -97,6 +97,9 @@ parse_mf_symlink(const u8 *buf, unsigned int buf_len, unsigned int *_link_len,
if (rc != 1)
return -EINVAL;
+ if (link_len > CIFS_MF_SYMLINK_LINK_MAXLEN)
+ return -EINVAL;
+
rc = symlink_hash(link_len, link_str, md5_hash);
if (rc) {
cifs_dbg(FYI, "%s: MD5 hash failure: %d\n", __func__, rc);